CNN and other news outlets were blocked on Friday from attending an off-camera White House press briefing that other reporters were hand-picked to attend, raising alarm among media organizations and First Amendment watchdogs.

The decision struck veteran White House journalists as unprecedented in the modern era, and escalated tensions in the already fraught relationship between the Trump administration and the press.

The New York Times, the Los Angeles Times, Politico, BuzzFeed, the BBC and the Guardian were also among those excluded from the meeting, which was held in White House press secretary Sean Spicer's office. The meeting, which is known as a gaggle, was held in lieu of the daily televised Q-and-A session in the White House briefing room.

When reporters from these news organizations tried to enter Spicer's office for the gaggle, they were told they could not attend because they were not on the list of attendees.

In a brief statement defending the move, administration spokeswoman Sarah Sanders said the White House "had the pool there so everyone would be represented and get an update from us today."